<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
    <style>
      .box {
        background: pink;
        width: 200px;
        height: 200px;
      }
    </style>
  </head>
  <body>
    <div class="box"></div>

    <script>
      let box = document.querySelector(".box");

      let lastTime = 0;
      box.onmousemove = function () {
        let nowTime = Date.now();

        if (nowTime - lastTime < 500) {
          return;
        }

        lastTime = nowTime;

        console.log("核心代码");
      };
    </script>
  </body>
</html>
